/*
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package net.l2emuproject.tools.algorithm;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import javolution.util.FastList;

/**
 * Descending Integer Sort Algorithm
 *  - Fast ordering system. - Can easily be ported elsewhere. - Can handle any
 * number of values, from a list or even from a map. - Handles duplicate values.
 * 
 * @author Tempy
 * 
 */
public class MultiSort {
	public static final int SORT_ASCENDING = 0;
	public static final int SORT_DESCENDING = 1;

	private List<?> _keyList;
	private List<Integer> _valueList;

	private boolean _isSortDescending;
	private boolean _isSorted;

	public MultiSort(int[] valueList) {
		_valueList = getIntList(valueList);
	}

	public MultiSort(Collection<Integer> valueList) {
		_valueList = getIntList(valueList);
	}

	public MultiSort(Object[] keyList, int[] valueList) {
		_keyList = getList(keyList);
		_valueList = getIntList(valueList);
	}

	public MultiSort(Map<?, Integer> valueMap) {
		_keyList = getList(valueMap.keySet());
		_valueList = getIntList(valueMap.values());
	}

	private final List<Integer> getIntList(Collection<Integer> valueList) {
		return Arrays.asList(valueList.toArray(new Integer[valueList.size()]));
	}

	private final List<Integer> getIntList(int[] valueList) {
		Integer[] tempIntList = new Integer[valueList.length];

		for (int i = 0; i < valueList.length; i++)
			tempIntList[i] = new Integer(valueList[i]);

		return Arrays.asList(tempIntList);
	}

	private final List<?> getList(Collection<?> valueList) {
		return getList(valueList.toArray(new Object[valueList.size()]));
	}

	private final List<Object> getList(Object[] valueList) {
		return Arrays.asList(valueList);
	}

	public final int getCount() {
		return getValues().size();
	}

	/**
	 * Definition of harmonic mean : http://en.wikipedia.org/wiki/Harmonic_mean
	 * should handle float value
	 * 
	 * @return
	 */
	public final double getHarmonicMean() {
		if (getValues().isEmpty())
			return -1;

		double totalValue = 0;

		for (Integer currValue : getValues())
			totalValue += (1.0 / currValue.doubleValue());

		return getCount() / totalValue;
	}

	public final List<?> getKeys() {
		if (_keyList == null)
			return new FastList<Object>();

		return _keyList;
	}

	public final int getFrequency(int checkValue) {
		return Collections.frequency(getValues(), checkValue);
	}

	public final int getMaxValue() {
		return Collections.max(getValues());
	}

	public final int getMinValue() {
		return Collections.min(getValues());
	}

	public final double getMean() {
		if (getValues().isEmpty())
			return -1;

		return ((double) getTotalValue() / (double) getCount());
	}

	public final double getStandardDeviation() {
		if (getValues().isEmpty())
			return -1;

		List<Double> tempValList = new FastList<Double>();

		double meanValue = getMean();
		int numValues = getCount();

		for (Integer value : getValues()) {
			double adjValue = Math.pow(value.doubleValue() - meanValue, 2);
			tempValList.add(adjValue);
		}

		double totalValue = 0;

		for (double storedVal : tempValList)
			totalValue += storedVal;

		return Math.sqrt(totalValue / (numValues - 1));
	}

	public final int getTotalValue() {
		if (getValues().isEmpty())
			return 0;

		int totalValue = 0;

		for (int currValue : getValues())
			totalValue += currValue;

		return totalValue;
	}

	public final List<Integer> getValues() {
		if (_valueList == null)
			return new FastList<Integer>();

		return _valueList;
	}

	public final boolean isSortDescending() {
		return _isSortDescending;
	}

	public final boolean isSorted() {
		return _isSorted;
	}

	public final void setSortDescending(boolean isDescending) {
		_isSortDescending = isDescending;
	}

	public boolean sort() {
		try {
			List<Object> newKeyList = new FastList<Object>();
			List<Integer> newValueList = new FastList<Integer>();

			// Sort the list of values in ascending numerical order.
			Collections.sort(getValues());

			int lastValue = 0;

			if (!isSortDescending()) {
				// If there are no keys, just return the ascendingly sorted
				// values.
				if (getKeys().isEmpty()) {
					_isSorted = true;
					return true;
				}

				// Iterate through the list of ordered numerical values.
				for (int i = getValues().size() - 1; i > -1; i--) {
					int currValue = getValues().get(i);

					// If the current value is equal to the last value, we have
					// at least one
					// duplicate that has been outputted already, so continue.
					if (currValue == lastValue)
						continue;

					// Set the last value to the current value, to prevent
					// duplication.
					lastValue = currValue;

					// Iterate through each key and match it to its stored
					// integer value,
					// then output both sets of data in the correct descending
					// numerical order.
					for (int j = 0; j < getKeys().size(); j++) {
						Object currKey = getKeys().get(j);

						if (getValues().get(j) == currValue) {
							newKeyList.add(currKey);
							newValueList.add(currValue);
						}
					}
				}
			} else {
				// If there are no keys, just sort the value list in reverse
				// order.
				if (getKeys().isEmpty()) {
					Collections.reverse(getValues());
					_isSorted = true;
					return true;
				}

				// Do the exact same as above, but in descending order.
				for (int i = 0; i < getValues().size(); i++) {
					int currValue = getValues().get(i);

					if (currValue == lastValue)
						continue;

					lastValue = currValue;

					for (int j = 0; j < getKeys().size(); j++) {
						Object currKey = getKeys().get(j);

						if (getValues().get(j) == currValue) {
							newKeyList.add(currKey);
							newValueList.add(currValue);
						}
					}
				}
			}

			_keyList = newKeyList;
			_valueList = newValueList;
			_isSorted = true;
			return true;
		} catch (Exception e) {
			return false;
		}
	}
}
